export declare class Set<T> {

private getIdentifier;

private _items;

constructor(getIdentifier: (item: T) => string, ...items: T[]);

get size(): number;

add(...items: T[]): void;

remove(item: T): void;

pop(): T;

has(item: T): boolean;

get items(): T[];

equals(that: Set<T>): boolean;

get empty(): boolean;

union(...those: Set<T>[]): Set<T>;

intersect(that: Set<T>): Set<T>;

filter(predicate: (item: T) => boolean): Set<T>;

map<U>(getIdentifier: (item: U) => string, transform: (item: T) => U): Set<U>;

mapSame(transform: (item: T) => T): Set<T>;

some(predicate: (item: T) => boolean): boolean;

minus(that: Set<T>): Set<T>;

take(): T;

product(that: Set<T>): Set<[T, T]>;

}

export declare class StringSet extends Set<string> {

constructor(...items: string[]);

}

export declare class NumberSet extends Set<number> {

constructor(...items: number[]);

}

export declare function range(min: number, max: number): Set<number>;